resistors on DOUT board

Parts Questions
1

hi, i want to put some colour changing leds in my midibox like these..

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=50423&item=5734082810&rd=1

these leds are supposed to be used with a 100 ohm resistor with a 5v supply..

my question is.. is it ok to just replace the 220ohm resistor in the dout board with a 100ohm or do i need to put an extra resistor between the dout board and the led?

best wishes

adam

2

givesHi Adam,

100Ohm will be fine (with 3,3Vf you will get 20mA LED-Current, which is OK for the DOUT driver chips - the limit is 25mA).

Just look at this thread for the right calculation of LED serial resistors:

http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=parts_q;action=display;num=1095722492;start=2#2

Raphael

3

many thanks  Raphael..

best wishes

adam